Measurement of $^{23}$Na(α,p)$^{26}$Mg at Energies Relevant to $^{26}$Al Production in Massive Stars

International audience; $^{26}$Al is an important radioisotope in astrophysics that provides evidence of ongoing nucleosynthesis in the Galaxy. The $^{23}$Na(α, p)$^{26}$Mg reaction has been identified by a sensitivity study as being one of the most important reactions for the production of $^{26}$Al in the convective C/Ne burning shell of massive stars. Owing to large uncertainties in previous experimental data, model calculations are used for the reaction rate of $^{23}$Na(α, p)$^{26}$Mg in this sensitivity study. Current experimental data suggest a reaction rate a factor of ∼40 higher than model calculations. However, a new measurement of this reaction cross section has been made in inverse kinematics in the energy range Ec.m.=1.28–3.15 MeV at TRIUMF, and found to be in reasonable agreement with the model calculation. A new reaction rate is calculated and tight constraints on the uncertainty in the production of Al26, due to this reaction, are determined.